JOE: This puzzle was one of my favorite to construct. The theme idea originated with Pete Collins, who envisioned the base path as SINGLE, DOUBLE, TRIPLE and HOMER. The problem was that they weren't the same length, so the grid faced symmetry challenges. I struggled for hours ... even making each theme entry plural. Subconsciously, I avoided the past tense — thinking they would be the same length as the plurals and harder to finesse into a coherent wording of the theme.
But I was wrong. When I finally came around to trying that notion, it was like hitting the jackpot; everything just fell into place. My advice to other constructors: look hard for natural symmetry and focus on variations that don't fight the fill process.

PETE: This was Joe and my fourth collaboration out of nine (and counting?). I think it was my favorite, along with our first (Sunday, August 3, 2008). Our early collaborations usually arose from me coming up with a crazy idea, getting stymied trying to construct a grid, then throwing the grid at Joe and begging him to finish it. Joe never backed down from a challenge — even if it did result in hours of teeth-gnashing and hair-pulling. I'm especially proud that this puzzle landed in "Will Shortz Picks His Favorite Puzzles".